Elevation overestimation in planned tracks on Locus Map 4
Hi,
I'm using Locus Map 4 on Android to draft my first track, and everything works well except for the total elevation gain, which seems significantly overestimated.
When I save my newly created track, Locus reports a total elevation gain of around 5000m. After using the "Update Elevation" function (which I don’t fully understand the purpose for planned tracks), the value increases further to 5300m. I’m unsure why this discrepancy occurs.
To verify, I recreated the same track from scratch and also imported the track created with Locus Map into four other apps (GPX Studio, Komoot, OutdoorActive, and BRouter Online). All of them reported a total elevation between 4300m and 4500m—much lower than Locus Map's 5300m. While I expect some variation between algorithms, a 1000m difference seems excessive, making me question the reliability of Locus's elevation data for planning my hikes.
Am I missing something? Are there any settings I can adjust to make Locus's elevation calculations more consistent with other apps?
Thanks in advance for any insights!
(you can find the GPX created with Locus Map in attachment)
The same problem 
Hello,
To be more precise, here are the total elevation indicated by several apps for the planned GPX created on Locus Map attached, for comparison purpose :
- Komoot : 4,280 m
- GPX Studio : 4,405m
- OutdoorActive : 4,555m
- mapy.cz : 4,535m
- BRouter : 4,466m
- Locus Map : 5044m, and 5274m after update elevation
Is it due to Locus Map being more accurate and taking into account event the smaller elevation changes, and maybe the other apps have more aggressive smoothing algorithms ?
Thanks for your information 👍
Hello,
To be more precise, here are the total elevation indicated by several apps for the planned GPX created on Locus Map attached, for comparison purpose :
- Komoot : 4,280 m
- GPX Studio : 4,405m
- OutdoorActive : 4,555m
- mapy.cz : 4,535m
- BRouter : 4,466m
- Locus Map : 5044m, and 5274m after update elevation
Is it due to Locus Map being more accurate and taking into account event the smaller elevation changes, and maybe the other apps have more aggressive smoothing algorithms ?
Thanks for your information 👍
Hi Vincent,
Elevation estimation is one of the toughest feature for mappping sofware, since it relies on a lot of different source data: Position accuracy of OSM-ways, precision of used elevation model, Optimal Altitude threshold - which is dependend on the atributes I mentioned before, as well as on the type of terrain of the track. Its totally different if a track is just runnen in flatland or slight hilly terrain, or in steep rocky terrain.
Locus Webplaner in combination with Openstreetmap source data and Sonny elevation model and an adjustable Altitude threshold slider is already the maximum we can get. The only alternative for tracks in "difficult" terrain would be to spend 1000s of €uros to pay a professsional surveyor using exakt data for position as well as for elevation ;-)
So I would do the following: use a quite high Altitude threshold (like 5m or even better 10m) to filter the track of Locus Webplaner, this will get you more realistic results for tracks in hilly terrain near steep slopes.
Tested on your track depending on Altitude-threshold:
3m: 5050m
5m: 4850m
10m: 4500m
20m: 4100m
Btw: Your "update elevation" value of 5274m seems to be quite strange. What elevation files did you use, I'm afraid not Sonny 1" DTMs... ;-)
Finally: Nobody beside a professional surveyor can tell you by guarantee if 4500m, 4850m or 5050m is more true for your specific route. You could check it by using a barometer-watch during your hike. But this method is also vulnerable to drifts because of weather and technical issues of the watches' internal filter.
Hi Vincent,
Elevation estimation is one of the toughest feature for mappping sofware, since it relies on a lot of different source data: Position accuracy of OSM-ways, precision of used elevation model, Optimal Altitude threshold - which is dependend on the atributes I mentioned before, as well as on the type of terrain of the track. Its totally different if a track is just runnen in flatland or slight hilly terrain, or in steep rocky terrain.
Locus Webplaner in combination with Openstreetmap source data and Sonny elevation model and an adjustable Altitude threshold slider is already the maximum we can get. The only alternative for tracks in "difficult" terrain would be to spend 1000s of €uros to pay a professsional surveyor using exakt data for position as well as for elevation ;-)
So I would do the following: use a quite high Altitude threshold (like 5m or even better 10m) to filter the track of Locus Webplaner, this will get you more realistic results for tracks in hilly terrain near steep slopes.
Tested on your track depending on Altitude-threshold:
3m: 5050m
5m: 4850m
10m: 4500m
20m: 4100m
Btw: Your "update elevation" value of 5274m seems to be quite strange. What elevation files did you use, I'm afraid not Sonny 1" DTMs... ;-)
Finally: Nobody beside a professional surveyor can tell you by guarantee if 4500m, 4850m or 5050m is more true for your specific route. You could check it by using a barometer-watch during your hike. But this method is also vulnerable to drifts because of weather and technical issues of the watches' internal filter.
Hi Sonny,
Thanks for your informative response! I now have a better understanding of the challenges involved in computing track elevation. You mentioned that it's possible to set a custom altitude threshold, but I can't find this option in Locus Map 4 (Android) or in the web planner. Could you point me to where I can change it?
Thanks!
Hi Sonny,
Thanks for your informative response! I now have a better understanding of the challenges involved in computing track elevation. You mentioned that it's possible to set a custom altitude threshold, but I can't find this option in Locus Map 4 (Android) or in the web planner. Could you point me to where I can change it?
Thanks!
I think you have to be Silver or Gold Member for this function! In Android app open the track in its library-folder > click onto the "pencil" icon on the bottom > "Altitude threshold" slider from 0m to 20m
Web-Planer: I can't find it myself, somebody oif Locus-Team will help you
I think you have to be Silver or Gold Member for this function! In Android app open the track in its library-folder > click onto the "pencil" icon on the bottom > "Altitude threshold" slider from 0m to 20m
Web-Planer: I can't find it myself, somebody oif Locus-Team will help you
Many thanks for your help Sonny !
Which version of Locus Map are you using ? I'm gold member and I'm currently using Locus 4.28.3 on Android. However, when I open a track from my library folder and click onto the "pencil" icon, I can only edit the following settings : track name, description, Activity type, folder and the style on map :(
Many thanks for your help Sonny !
Which version of Locus Map are you using ? I'm gold member and I'm currently using Locus 4.28.3 on Android. However, when I open a track from my library folder and click onto the "pencil" icon, I can only edit the following settings : track name, description, Activity type, folder and the style on map :(
https://docs.locusmap.app/doku.php?id=manual:faq:wrong_gps_data#:~:text=Custom%20altitude%20threshold,-Those%20who%20are&text=open%20Expert%20settings%20%3E%20Customize%20altitude,altitude%20threshold%20with%20the%20slider
https://docs.locusmap.app/doku.php?id=manual:faq:wrong_gps_data#:~:text=Custom%20altitude%20threshold,-Those%20who%20are&text=open%20Expert%20settings%20%3E%20Customize%20altitude,altitude%20threshold%20with%20the%20slider
Oh, thanks a lot! Enabling the expert settings worked perfectly, I can now adjust the threshold !
I’d like to share my humle opinion as a new Locus Map user, in case the Locus team sees this thread: I appreciate that Locus Map provides highly accurate elevation data by default, using a 5-meter altitude threshold. However, I think this information should be presented more clearly within the app, and users should be able to adjust the altitude threshold more easily—without needing to enable an expert setting. Right now, it feels too hidden. I think that this should be ideally a global setting for all tracks, with the option to override it per track.
Additionally, and once again as a beginner user, I found it almost impossible - despite reading the documentation - to understand what really happens after clicking "Update Elevation." It wasn’t clear why my total elevation changed from 5,000m to 5,300m. Now I understand that this button lowers the altitude threshold from 5m to 3m to make the elevation data more accurate, and thus leading to a higher total elevation. I think the app and/or the documentation should explain this more clearly so users can better understand its effect.
I may be wrong, but it seems that most outdoor apps and hiking websites out there appear to use a much higher altitude threshold (thus less sensitive), which generally results in a much lower total elevation compared to Locus Map.
While it’s great that Locus Map provides a more precise calculation by default, users should have the option to adjust this setting and choose a more "conventional" threshold if needed. This would help having an approximative consistency with other sources and apps, making it much easier to compare elevation data and plan routes effectively.
Anyway, thanks again for your help Sonny, and a huge thanks to the Locus team for your great work on this amazing app!
Oh, thanks a lot! Enabling the expert settings worked perfectly, I can now adjust the threshold !
I’d like to share my humle opinion as a new Locus Map user, in case the Locus team sees this thread: I appreciate that Locus Map provides highly accurate elevation data by default, using a 5-meter altitude threshold. However, I think this information should be presented more clearly within the app, and users should be able to adjust the altitude threshold more easily—without needing to enable an expert setting. Right now, it feels too hidden. I think that this should be ideally a global setting for all tracks, with the option to override it per track.
Additionally, and once again as a beginner user, I found it almost impossible - despite reading the documentation - to understand what really happens after clicking "Update Elevation." It wasn’t clear why my total elevation changed from 5,000m to 5,300m. Now I understand that this button lowers the altitude threshold from 5m to 3m to make the elevation data more accurate, and thus leading to a higher total elevation. I think the app and/or the documentation should explain this more clearly so users can better understand its effect.
I may be wrong, but it seems that most outdoor apps and hiking websites out there appear to use a much higher altitude threshold (thus less sensitive), which generally results in a much lower total elevation compared to Locus Map.
While it’s great that Locus Map provides a more precise calculation by default, users should have the option to adjust this setting and choose a more "conventional" threshold if needed. This would help having an approximative consistency with other sources and apps, making it much easier to compare elevation data and plan routes effectively.
Anyway, thanks again for your help Sonny, and a huge thanks to the Locus team for your great work on this amazing app!
A short word on the altitude estimations of the other providers: Although all of them also use OSM-ways as basis, I'm not sure who of them uses Sonny-Lidar elevation data like Locus Webrouter, and who "just" satellite-based rough sources like SRTM or ALOS. In this cases their estimations would be "ok" here with your route "by chance", but major wrong with some routes in other European regions. There are some "testregions" where SRTM for example suffers of major errors and routing-providers based on them are completely false, see: https://help.locusmap.eu/topic/33920-web-planer-inaccurate-contour-lines
So the one and only parameter remaining for Locus-users to play around (after they installed Sonny 1" elevation files on their phone) is altitude Threshold setting. It's not easy for Locus team to define a default threshold, which is good in flat and rocky terrain as well. 3m maybe is to less even with good OSM+Lidar data in mountaineous terrain. 10m is too much in flat or gentle hilly surroundings, since every little up-down below 10m would completely get lost in estimation. So maybe a default of 5m (instead of 3m right now even for "update elevation data"), and a somehow better placement of threshold slider & short doku/values to choose from based on terrain of route, as mentioned above by @Vincent , would be an idea... ;-)
A short word on the altitude estimations of the other providers: Although all of them also use OSM-ways as basis, I'm not sure who of them uses Sonny-Lidar elevation data like Locus Webrouter, and who "just" satellite-based rough sources like SRTM or ALOS. In this cases their estimations would be "ok" here with your route "by chance", but major wrong with some routes in other European regions. There are some "testregions" where SRTM for example suffers of major errors and routing-providers based on them are completely false, see: https://help.locusmap.eu/topic/33920-web-planer-inaccurate-contour-lines
So the one and only parameter remaining for Locus-users to play around (after they installed Sonny 1" elevation files on their phone) is altitude Threshold setting. It's not easy for Locus team to define a default threshold, which is good in flat and rocky terrain as well. 3m maybe is to less even with good OSM+Lidar data in mountaineous terrain. 10m is too much in flat or gentle hilly surroundings, since every little up-down below 10m would completely get lost in estimation. So maybe a default of 5m (instead of 3m right now even for "update elevation data"), and a somehow better placement of threshold slider & short doku/values to choose from based on terrain of route, as mentioned above by @Vincent , would be an idea... ;-)
In principle, it doesn't matter whether it's a few meters higher or lower.
It is much more important that you always work with the same settings. You know that with these settings, 500 m is less for you and 1000 m is a lot. The altitude meters are there for you to determine whether it is a hard tour or an easy one.
In principle, it doesn't matter whether it's a few meters higher or lower.
It is much more important that you always work with the same settings. You know that with these settings, 500 m is less for you and 1000 m is a lot. The altitude meters are there for you to determine whether it is a hard tour or an easy one.
Hi guys,
at the moment, Locus Map works with two sets of elevation data (EDIT):
1) accurate 1" offline data by Sonny is implemented in LoMaps' elevation contour lines and LoRouter calculations.
2) less accurate 3" data streamed online or downloaded from Locus Store, is used for terrain shading, dynamic elevation, and the "update elevation" purposes. The "update elevation" helps in cases like deviations due to bad GPS data, when you download a route without elevations etc.
The reason we still use the data 2 is that we haven't developed a viable distribution system that would work for this purpose.
To sum it up:
When you plan a route in the route planner, it is not necessary (or even recommended) to use the "update elevation" feature.
Sonny, thanks for the explanation of the altitude threshold thing.
Hi guys,
at the moment, Locus Map works with two sets of elevation data (EDIT):
1) accurate 1" offline data by Sonny is implemented in LoMaps' elevation contour lines and LoRouter calculations.
2) less accurate 3" data streamed online or downloaded from Locus Store, is used for terrain shading, dynamic elevation, and the "update elevation" purposes. The "update elevation" helps in cases like deviations due to bad GPS data, when you download a route without elevations etc.
The reason we still use the data 2 is that we haven't developed a viable distribution system that would work for this purpose.
To sum it up:
When you plan a route in the route planner, it is not necessary (or even recommended) to use the "update elevation" feature.
Sonny, thanks for the explanation of the altitude threshold thing.
Hi,
Thanks for the additional insights, Sonny! I now have a much better understanding of how complex this topic is.
Also, thanks, Michal, for clarifying the purpose of the "Update Elevation" button—I really appreciate the explanation.
@freischneider, I completely agree with you about the importance of working with consistent settings and data across tracks. Coming from another app that tends to show lower total elevation gains compared to Locus Map, I suppose I just need to adjust my own reference scale and "re-map" elevation data with my future real-life hikes on the terrain.
I must admit, before starting this thread, I wasn’t fully aware of how intricate elevation data processing can be - this discussion has been truly insightful!
Hi,
Thanks for the additional insights, Sonny! I now have a much better understanding of how complex this topic is.
Also, thanks, Michal, for clarifying the purpose of the "Update Elevation" button—I really appreciate the explanation.
@freischneider, I completely agree with you about the importance of working with consistent settings and data across tracks. Coming from another app that tends to show lower total elevation gains compared to Locus Map, I suppose I just need to adjust my own reference scale and "re-map" elevation data with my future real-life hikes on the terrain.
I must admit, before starting this thread, I wasn’t fully aware of how intricate elevation data processing can be - this discussion has been truly insightful!
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